The present invention relates to a multi-position ratchet mechanism for holding a surgical retractor blade and, more particularly to a quick-release ratchet mechanism which permits the retractor blade to be tilted and rotated into the wound so that the organ may be retracted and lifted at the same time.
A surgical retraction systems is described in U.S. Pat. No. 4,254,763. This patent, incorporated by reference, describes the ability to utilize a retractor ring to retract organs in the plane of the ring.
An improvement for use with the ring of U.S. Pat. No. 4,354,763 was disclosed in U.S. Pat. No. 4,424,724. The ""724 Patent, also incorporated by reference, discloses a multi-position ratchet mechanism for holding a surgical retractor blade allowing the blade to be pivoted into the wound from a ring and retracted at the same time. This device allowed the retractor to be tilted, or pivoted, into the wound and retracted with one motion.
The ratchet mechanism of the ""724 patent only allows for pivoting in a single plane about the ratcheting mechanism perpendicularly to the ring to which the mechanism is secured. A need exists for rotation in other planes as well, preferably in a plane substantially perpendicular to the plane of the operation of the ratcheting mechanism, i.e., the plane of pivoting, or the plane of the ring.
Furthermore, the ratchet mechanism of the ""724 patent is not believed to adequately secure the retractor to the ring. Specifically, the ratchet holder relies on tension of the retractor blade to pull the holder forward so that the edge of a dowel pin engages indentations of the ring to prevent the circumferential sliding of the ratchet holder and to prevent the ratchet holder from falling off the ring. However, there are instances when this necessary tension may not be present or adequate and the ratchet holder would have little, if any, resistance to prevent coming off the ring. Furthermore, torque applied to the ratchet holder may also cause problems. Accordingly, a need exists to restrain the ratchet holder from moving away off of the ring.
The multi-position ratchet mechanism of the preferred embodiment provides a multi-position ratchet mechanism for holding the retractor blade for permitting it to be pivoted into a wound and retracted at the same time which may be thought to simulate the natural xe2x80x9ctoe-inxe2x80x9d method of retraction one could achieve with the hand. The mechanism of the present invention also permits the position of the ratchet mechanism to be moved circumferentially about the support ring and allow for rotation about the selected position relative to the support ring. Furthermore the ratchet mechanism is preferably configured to securely connect with the support ring.
The multi-position ratchet mechanism includes a ring holder, which is mounted onto the support ring, such as an oval support ring. Selective positioning of the ratchet holder relative to the ring may be achieved through the use of a transverse slot in the ratchet holder which receives a thickness of the ring therein. A retention mechanism is utilized to prevent the ring from inadvertently coming out of the transverse slot.
The retention mechanism restrains the ring in the transverse slot of the ring holder. Specifically, the ring typically has a width which terminates proximate to the end transverse slot when the ring is installed in the transverse slot. The retention mechanism is moved into position to prevent movement of the ring out of the transverse slot. In the preferred embodiment, the retention mechanism is pivoted in and out of position with a lever.
The multi-position ratchet also preferably includes the ability to rotate relative to the ring as well as the ability to be secured in a fixed radial orientation relative to the ring upon rotation to a desired angle. Opposing serrated washers which cooperate to resist rotation when engaged maybe utilized. The serrated washers maybe engaged or disengaged utilizing a cam, or otherwise.